“Moneyball” changed the way people thought about baseball--particularly the value of walks. The one argument that really swept through baseball fandom was that if teams looked past batting averages and snatched up patient hitters with high on-base-percentages, they could gain a competitive advantage.

Despite the wide influence of that argument, walks have actually become less common since “Moneyball” came out in 2003. Players aren’t walking more, they’re walking less. And league-wide on-base-percentages have fallen to 40-year low. Why is that? In large part, it’s the old story of cat and mouse. Once more players started looking for walks, pitchers stopped offering them. That’s been true across the league, and true for the Red Sox.

Are walks really less common?

There have been fewer walks in recent years than at any time since the mid-1970s. This year, in particular, we’re on track to see the lowest number of walks since 1968.

Strikeouts, by contrast, have continued their decades-long ascension. They’ve increased by 20 percent since 2003 and by 60 percent since 1980.

Why are there fewer walks?

It’s not because hitters have gotten less patient. If you look at the average number of pitches for each plate appearance, it has actually gone up in recent years, from 3.75 in 2003 to 3.83 this year.

What has changed is that pitchers are throwing more strikes. Roughly one extra strike for every hundred pitches, or 1-2 extra strikes per game. That may not sound like a lot, but the relationship between pitcher and batter is a delicate one, and even small shifts in strategy can make a big difference.

Do these patterns hold for the Red Sox?

Indeed they do.

Today’s Red Sox are walking less then their 2003 predecessors. On that 2003 team—anchored by Manny Ramirez, Bill Mueller, and Nomar Garciaparra—about one in every 10 plate appearances ended up as a walk. In 2014, it’s down to one in 11. The big exception is Mike Napoli, who is walking nearly once every six times he steps to the plate.

Turning to pitching, the 2003 starters gave up 2.86 walks per 9 innings. This year, it’s slightly lower, at 2.80 walks per nine innings. More telling, Jon Lester and John Lackey averaged 2 and 2.1 respectively, far better than any pitcher on the 2003 team, including Pedro Martinez.

Does this mean the Moneyball argument was wrong?

Not exactly. As I say, hitters really have gotten more patient in recent years. The reason this hasn’t translated into more walks is because the world around them has shifted.

It’s evidence of a truth beyond Moneyball. Every new strategy breeds its own counter-strategy. In this case, the moment teams started to value walks and players began to practice patience, pitchers responded by throwing more strikes--and the league helped, indirectly, by encouraging a larger strike zone.

Evan Horowitz digs through data to find information that illuminates the policy issues facing Massachusetts and the U.S. He can be reached at evan.horowitz@globe.com. Follow him on Twitter @GlobeHorowitz